Mitsubishi Galant 9G. Manual — part 1188

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <3.8L ENGINE>

13B-1052

STEP 5. Using scan tool MB991958, check actuator test
items 01, 02, 03, 04, 05, 06: Injector.

CAUTION

To prevent damage to scan tool MB991958, always turn the
ignition switch to the "LOCK" (OFF) position before con-
necting or disconnecting scan tool MB991958.
(1) Connect scan tool MB991958 to the data link connector.
(2) Turn the ignition switch to the "ON" position.
(3) Check following items in the actuator test. Refer to Actuator

Test Reference Table

P.13B-1152

.

a. Item 01, 02, 03, 04, 05, 06: Injector.

(4) Turn the ignition switch to the "LOCK" (OFF) position.
Q: Are they operating properly?

YES : Go to Step 6.
NO : Refer to DTC P0201

P.13B-481

, P0202

P.13B-493

,

P0203

P.13B-504

, DTC P0204

P.13B-516

,

P0205

P.13B-527

, P0206

P.13B-539

− Injector Circuit.

STEP 6. Using scan tool MB991958, check data list.
(1) Turn the ignition switch to the "ON" position.
(2) Check the following items in the data list. Refer to Data List

Reference Table

P.13B-1137

.

a. Item 21: Engine Coolant Temperature Sensor.

(3) Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is the sensor operating properly?

YES : Go to Step 7.
NO : Repair or replace it. Then confirm that the malfunction

symptom is eliminated.

AC305412

AB

MB991910

DATA LINK

CONNECTOR

MB991824

MB991827

AC305412

AB

MB991910

DATA LINK

CONNECTOR

MB991824

MB991827

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <3.8L ENGINE>

13B-1053

STEP 7. Check the fuel pressure.
Refer to On-vehicle Service

− Fuel Pressure Test

P.13B-1179

.

Q: Is the fuel pressure normal?

YES : Go to Step 8.
NO : Repair or replace it. Then confirm that the malfunction

symptom is eliminated.

STEP 8. Check the ignition timing.
Refer to GROUP 11, On-vehicle Service

− Ignition Timing

Check

P.11C-8

.

Q: Is the ignition timing normal?

YES : Check the following items, and repair or replace the

defective items.

a. Check the ignition coil and spark plugs.
b. Check compression pressure.
c. Check the engine oil viscosity.
d. Check the EGR valve.

Then confirm that the malfunction symptom is

eliminated.

NO : Check that the crankshaft position sensor and timing

belt cover are in the correct position. Then confirm
that the malfunction symptom is eliminated.

INSPECTION PROCEDURE 12: When the Engine Is Hot, It Stalls at Idle (Die Out).

.

COMMENT

• In cases such as the above, the ignition system,

air/fuel mixture, electronic control throttle valve
system or compression pressure may be faulty. In
addition, if the engine suddenly stalls, the cause
may also be a connector damage.

.

TROUBLESHOOTING HINTS (The most
likely causes for this case:)

• Malfunction of the ignition system.

• Malfunction of air/fuel ratio control system.

• Malfunction of the electronic control throttle valve

system.

• Malfunction of the EGR valve.

• Vacuum leak.

• Improper connector contact.

DIAGNOSIS

Required Special Tools:

• MB991958: Scan Tool (MUT-III Sub Assembly)

• MB991824: V.C.I.

• MB991827: USB Cable

• MB991910: Main Harness A

STEP 1. Check if the battery terminal is disconnected.
Q: Has the battery terminal been disconnected lately?

YES : Start the engine and let it run at idle for approximate

10 minutes after engine warm up. Then, if a
malfunction occurs, go to step 2.

NO : Go to Step 2.

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <3.8L ENGINE>

13B-1054

STEP 2. Using scan tool MB991958, read the diagnostic
trouble code (DTC).

CAUTION

To prevent damage to scan tool MB991958, always turn the
ignition switch to the "LOCK" (OFF) position before con-
necting or disconnecting scan tool MB991958.
(1) Connect scan tool MB991958 to the data link connector.
(2) Turn the ignition switch to the "ON" position.
(3) Read the DTC.
(4) Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is the DTC set?

YES : Refer to Diagnostic Trouble Code Chart

P.13B-34

.

NO : Go to Step 3.

STEP 3. Using scan tool MB991958, check actuator test
items 01, 02, 03, 04, 05, 06: Injector.

CAUTION

To prevent damage to scan tool MB991958, always turn the
ignition switch to the "LOCK" (OFF) position before con-
necting or disconnecting scan tool MB991958.
(1) Connect scan tool MB991958 to the data link connector.
(2) Turn the ignition switch to the "ON" position.
(3) Check following items in the actuator test. Refer to Actuator

Test Reference Table

P.13B-1152

.

a. Item 01, 02, 03, 04, 05, 06: Injector.

(4) Turn the ignition switch to the "LOCK" (OFF) position.
Q: Are they operating properly?

YES : Go to Step 4.
NO : Refer to DTC P0201

P.13B-481

, P0202

P.13B-493

,

P0203

P.13B-504

, DTC P0204

P.13B-516

,

P0205

P.13B-527

, P0206

P.13B-539

− Injector Circuit.

AC305412

AB

MB991910

DATA LINK

CONNECTOR

MB991824

MB991827

AC305412

AB

MB991910

DATA LINK

CONNECTOR

MB991824

MB991827

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <3.8L ENGINE>

13B-1055

STEP 4. Checking by depressing and releasing the
accelerator pedal.
Q: Does the engine stall right after the accelerator pedal is

released?
YES : Refer to On-vehicle Service

− Throttle Body (Throttle

Valve Area) Cleaning

P.13B-1178

.

NO : Go to Step 5.

STEP 5. Engine stall reproduction test.
Q: Is it easy to reproduce the engine stall?

YES : Go to Step 6.
NO : Check if the following signals change suddenly by

wiggling the circuit harness and connectors.

a. Crankshaft position sensor signal.
b. Mass airflow sensor signal.
c. Injector drive signal.
d. Primary and secondary ignition signal.
e. Fuel pump drive signal.

f. PCM power supply voltage.

Repair or replace it. Then confirm that the malfunction

symptom is eliminated.

STEP 6. Using scan tool MB991958, check data list.

CAUTION

To prevent damage to scan tool MB991958, always turn the
ignition switch to the "LOCK" (OFF) position before con-
necting or disconnecting scan tool MB991958.
(1) Connect scan tool MB991958 to the data link connector.
(2) Turn the ignition switch to the "ON" position.
(3) Check the following items in the data list. Refer to Data List

Reference Table

P.13B-1137

.

a. Item 13: Intake Air Temperature Sensor.
b. Item 25: Barometric Pressure Sensor.

c. Item 21: Engine Coolant Temperature Sensor.

d. Item 69: Right Bank Heated Oxygen Sensor (rear).
e. Item 39: Right Bank Heated Oxygen Sensor (front).

f. Item 59: Left Bank Heated Oxygen Sensor (rear).

g. Item 11: Left Bank Heated Oxygen Sensor (front).
h. Item 27: Power Steering Pressure Switch.

i. Item 68: EGR valve (stepper motor).
j. Item 79: Throttle position sensor (main).

(4) Turn the ignition switch to the "LOCK" (OFF) position.
Q: Are they operating properly?

YES : Go to Step 7.
NO : Repair or replace it. Then confirm that the malfunction

symptom is eliminated.

AC305412

AB

MB991910

DATA LINK

CONNECTOR

MB991824

MB991827